Do-it-yourself floor screed in the apartment in stages. Do-it-yourself floor screed procedure

The arrangement of the floor screed is a process that, with a good repair, and even more so construction, no one can avoid. And in this process, a lot of dusty, dirty and wet work is usually done. After them, the screed should be left to “ripen”, “helpfully” moisten for several days and not walk on the floor for quite a long time. Not to mention the money spent.

To make the result pleasing to the eye, and the process to take place in an organized and fast manner, we suggest that you read this article, which will tell readers how to make a floor screed yourself. Moreover, there is nothing supernatural and prohibitively difficult in this, which we intend to convince our readers of.

Floor screed is an intermediate layer that is organized between any base and the floor finish. Why do you need a screed?

• To give floors the required rigidity and strength according to expected loads.
• To level the floor horizontally, or, conversely, to give the desired slope in some areas, for example, in showers.

• No matter how funny it sounds, but the screed is sometimes made for thermal insulation, as some of its types are capable of this.
• The screed in underfloor heating plays the role of a large radiator, therefore, we can say that it is needed for the necessary heat absorption and distribution.
• For sheltering elements of engineering systems: electrical wiring, heating pipes and floor heating coils, sewer pipes.

• For shelter and protection of the thermal insulation layer from mechanical stress.

In some cases, the screed itself is already the floor finish. For example, in garages, any technical or industrial premises, where another coating will not be laid in the future. Then, we can say that such a screed - single layer .

In many other cases, ties do two-layer .

• The first layer levels the surface horizontally, or gives the desired slopes. Usually it is performed from a cement-sand mixture or concrete. It is customary to say that the first layer is rough screed . On it in the future, you can lay tiles or porcelain tiles.
• The second layer is called finishing screed . It already makes the surface perfectly flat, under the floor finish, for example, under a laminate, parquet, carpet. Very often, a finishing screed is performed giving a perfect surface when properly applied.

The screed can be laid on different grounds: compacted soil, concrete or even wood. Depending on the connection with the bases of the screed, you can divided into the following kinds:

• Linked screed , which is characterized by the fact that it is firmly bonded to the previous layer. More often it is a concrete screed on a concrete floor slab. The necessary adhesion and homogeneity of this design also provide excellent mechanical strength. Such screeds can only be done in those rooms where the humidity of the base will not be high. They are used on the second and subsequent floors of various buildings.

• Screed on the separating layer . This design should be in contact of two different materials. For example, when a concrete screed is made on the ground. Or in the case when a gypsum or dry screed is laid on concrete. And also the use of a separating layer is mandatory if the humidity of the underlying layer is above the norm. As a separator, various rolled materials based on bitumen (roofing material), polymer films or coating compositions can be used. Obviously, the screed will already be a separate structure, so it is desirable to reinforce it and make it at least 3-5 cm thick.
• floating floor screed is a continuation of the previous one. It is necessarily arranged if any insulation is required. The floating screed is separated from the base by a layer of insulation along with waterproofing. It is also necessarily separated from the walls. It can be a heater, but of a smaller thickness or a special damper tape. Warm water floors are necessarily accompanied by a floating screed, since in addition to mechanical loads, such a screed will still change in size due to temperature effects. Working in such conditions forces the use of reinforcement and has a thickness of at least 5 cm.
• Prefabricated or dry floor screed. In our country, this is a relatively new phenomenon, but in Europe it has been used for a long time. On the prepared and insulated base of such a screed, filler is poured in the form of dry bulk material. Most often used granular, which is a good heat and sound insulator. Sheets are laid on top of it gypsum fiber plates attached to each other. Such a screed is equipped very quickly and this is its main advantage. However, dry screeding can only be done in rooms with guaranteed low humidity and with a low or medium load on the floor.

Screeds can also vary in laying methods. Let's list them:

• Solid floor screed, performed by a "wet" method . This is the most common, you can even say the classic way. The solution, closed with water, is applied to the prepared base and leveled along the beacons by the rule. Since the main binder for the wet method is 95% cement, such screeds gain full strength only after 28 days, which is a big disadvantage.
• Solid floor screed, performed in a "semi-dry" way . This direction began to develop relatively recently. The meaning of this approach is that exactly the amount of water that is necessary for cement hydration is added to the working solution. Such screeds dry out faster - the next day you can already walk, and lay the tiles in a week. A plasticizer is introduced into the solution, which improves mobility and plasticity during laying. In addition, semi-dry screeds often use micro-reinforcement with fiber (polypropylene or basalt). The screed with fiber is better in terms of strength, wear resistance, stretching and bending than with classic wire mesh reinforcement. The technology of laying semi-dry screeds is more complicated, the preparation of the solution requires precise adherence to the recipes.

Laying, leveling and sanding semi-dry screed - all in one day

• Solid floor screed with self-leveling compounds . This method also applies to "wet". As we noted in this way, it is very convenient to make a finishing screed. Such screeds are made with a thin layer of 0.5-20 mm, first of all for economic reasons, since dry mixes for the preparation of solutions are very expensive. But the laying technology and the result observed later are above all praise. The working solution is simply poured over the surface in stripes, rolled with a spiked roller to remove bubbles, and, in fact, that's it.
• Dry or prefabricated floor screeds. We have already mentioned them before. You can read more about them on our website.

All floor screeds, with the exception of prefabricated (dry), are made on based on two main binders component - cement or gypsum. There are also others - magnesia, bituminous, anhydrite - but they are not used for housing construction, and therefore will not be considered. We note the strengths and weaknesses of these two basic materials.

cement screed prices

cement strainer

• Cement based screeds have high strength, durability and most importantly - resistance to water. The weaknesses of such screeds are the tendency to shrink when dried and the long maturation time.
• Gypsum based screeds strong enough and durable. The solutions are very plastic and do not shrink when dried. They have good thermal insulation properties. Can be applied to any substrate, including wood. The maturation period is several times less than that of cement screeds. But there is one main disadvantage - this is the "fear" of water.

Naturally, in addition to the binder component, which is the main one, the composition of any modern solution or dry mixture also includes other components: fillers and modifiers, both of natural origin and obtained in chemical industries. Therefore, modern mixtures cannot be called only cement or gypsum. It's more correct to speak cement-polymer or gypsum-polymer .

In cement screeds, polystyrene chips are often used as one of the fillers, which gives the coating thermal insulation properties. The bearing capacity and rigidity of such screeds is less, this must be taken into account. At the same time, a second leveling and strengthening layer with more durable fillers is also required.

If you want to create a screed with thermal insulation properties of great thickness, then another material comes to the rescue - expanded clay, obtained by firing clay. This is an excellent filler that has good thermal insulation properties, it is inert, does not decompose with water and is quite durable. Another plus of the use of expanded clay as a filler is a significant saving of cement and a reduction in the labor intensity of laying the screed.

With the help of fillers and modifiers, modern cement screeds dry faster and shrink less, and gypsum screeds partially overcome the “fear of water”. But, I must say that "hereditary diseases" in one form or another still remain. Therefore, cement-based screeds are still the most versatile. There is also a place for gypsum-polymer, but only in dry rooms, where exposure to water in any form is excluded.

Let's move on to the practical part of the implementation of the floor screed. To do this, we will divide this process into stages, each of which will be considered separately. What are these stages?

• Foundation preparation;
• Displaying lighthouses;
• Solution preparation;
• Floor screed device.

At each stage, we will try to explain the whole process in detail, accompanying with photos and videos. So let's start.

Preparation of the base for floor screed

We will consider only three types of foundations: soil, old floor screed and concrete surface. We will not deliberately consider a wooden base, since we believe that it is easier to equip floors on it without a screed using other levelers: plywood or OSB sheets.

The basis of the screed - soil

The best time to equip rough floor screeds on the ground is the stage of foundation construction. Then all earthwork and other work is much easier to carry out. And in modern construction they do just that. If this is done in an existing house, then, of course, the task is greatly complicated, but it is not fundamentally different. Let's note the main stages of preparation.

• The first thing to do is to choose the soil to a depth of at least 50 cm. In each case, the depth may be different. The bottom of the pit is cleaned and compacted.
• If the soil is clayey or loamy soil, then it is necessary to take care of drainage so that moisture does not “prop up” the floors from below.
• Next, the creation of the so-called filtration or drainage layer begins. To do this, sand is poured with a layer of at least 100 mm. More is possible, but note that 100 mm is the lower limit. The sand is then rammed with a manual rammer or with an electric or petrol rammer.

• It should be noted that the maximum allowable layer of sand you need to tamp - this is 200 mm. If a larger layer is planned, then the ramming work is divided into stages, but no more than 200 mm at a time. In the process of tamping, it is necessary to periodically water the sand with water from a hose.
• A layer of crushed stone or gravel of a large fraction is poured onto the sand. The minimum thickness is also 100 mm. This layer is compacted manually or mechanically. Crushed stone or gravel helps to better compact the sand layer and give the filter layer a rigid base.

The next step depends on how much more space is left to the level from which the future floor screed on the ground will already be formed.

Prices for vibrating plates

vibrating plates

• If there is still 150-200 mm available, then a layer of concrete with the addition of expanded clay can be laid on a gravel-sand cushion. This will be the first stage of thermal insulation, but it will still not be enough for most regions of Russia. per layer expanded clay concrete then a layer of 40-100 cm of “lean” concrete is laid and compacted. It is called "skinny" because it has a low content of a binder - cement. Lean concrete usually has grades M 100 (B7.5) or M 150 (B10). The task of such a layer is not to carry the main load, but to fill in the irregularities of the underlying layer, level the surface and prepare it for waterproofing.
• Another case in the preparation of soil floors for a screed is the absence of 150-200 mm for the expanded clay concrete layer. Then lean concrete comes to the rescue again. It is laid directly on the rubble, and the concrete layer should also not exceed 100 mm, 40-60 mm is more than enough. When laying, be sure to ram it so that the solution penetrates into the space between the rubble stones. With the help of a trowel, a rule and a grater, it is necessary to form a flat outer surface, which will be the basis for the future floor screed.

The next steps are the same for both cases. After drying the "laying" of lean concrete, it is necessary to carry out waterproofing measures. For this, bituminous mastics are used, with which the entire surface is coated with at least two layers. Do not forget about the fact that mastic must be coated with walls to a height not less than the height of the floor screed. In regions with a high level of groundwater, after mastic, it will not be superfluous to roll on the basis of bitumen or dense plastic film, overlapped.

Screed base - old screed

Those who got this option should not be envied, since in most cases the old screed will have to be dismantled. Even if it gives the impression of reliability and impeccability. Even if it does not “blow” when tapped and has a flat surface without cracks. Let's give the arguments.

a new screed, the "perfection" of the old one can easily be broken. Under new conditions, delamination from the base can occur, cracks that will affect the top layer as well.

A new screed over the old one is an additional load on the base. This is especially true for ceilings on the upper floors. A slab with an area of ​​1 m² of a cement-sand screed 5 cm thick has a mass of 110 kg.

Each screed “eats up” at least 5 cm of space, which is already very significant in standard housing. In addition, there may be problems with radiators, pipes suitable for them, thresholds and door leaf.

Ties are never made so that they cannot be dismantled. It seems to be logical sometimes to connect two layers with reinforcing bars or wire, but no. Even connected concrete screeds are held together only by adhesion and will delaminate quite easily under mechanical stress.

To dismantle the screed, it is best to call a team of workers who specialize in this. From experience, it will be much cheaper this way. You should not even try to do it alone, as both the owners and neighbors will be exhausted if the screed is removed in an apartment building. A professional team immediately arrives with all the necessary mortising and stone-cutting equipment, shovels, garbage bags, and a vacuum cleaner. They immediately take away all the garbage collected during mortising work and the owner does not have to worry about calling a separate car. The work of professionals goes on in a continuous mode: one or two people are hammering, another one or two immediately collect the garbage in bags, and the rest take it out and load it into the car.

The main task of the owners is to negotiate with everyone who may be uncomfortable with noise. In panel houses - this is the whole house. And, of course, make sure that after the departure of the brigade on the site and in the entrance there are no traces of the presence of "noisy guys" and dust from the old screed.

In private houses, everything is simpler, you don’t have to negotiate with neighbors. You can try it yourself, but you still can’t do without helpers. To dismantle the old screed, you will definitely need a powerful puncher with a cartridge not SDS +, not SDS-Max. The puncher will also need chisels. Jackhammers are sometimes used, but this step can only be taken if this tool is in the hands of a professional. Improper use of a powerful jackhammer can easily break a concrete reinforced slab.

In addition to a puncher, a 230 mm grinder with a stone-cutting disc, a construction vacuum cleaner, shovels, brooms, and a large number of durable bags can be very useful. Work must be carried out in working clothes made of dense fabric and in a headdress, gloves, mask or glasses. Since there will be a lot of dust, a respirator is required. It is better to protect your hearing organs with headphones, as there will be a lot of noise. Not every master has such a set of tools in his arsenal, but all this is rented in any region. In order not to overpay for rent, it is better to fit all the work in one day, so assistants are definitely needed. Let's describe the main stages of dismantling the old screed.

• If there are electrical wiring routes, heating or water supply pipes in the room under the screed, then a circuit is desirable, which should remain after installation. If it is not there, then you will have to use a special device - a hidden wire and metal detector, which needs to examine the entire area of ​​\u200b\u200bthe room and mark these places on the surface with a bright marker.
• It is better to start dismantling the screed from the entrance to the room and further move deeper into it. So it will be easier to immediately remove the exfoliated pieces of the old screed. But before starting the dismantling, it is necessary to carry out "exploratory drilling". To do this, in a small area, cuts are made with a grinder with a stone-cutting disc, and then small pieces of the screed are broken off with a puncher with a spatula or a jackhammer to get to the next “cultural layer”. If that layer is the desired carrier plate, then you need to measure the thickness of the removed screed with a tape measure in order to know the landmark.
• It is necessary to start to beat off the old screed with small revolutions of the perforator engine and first chip off in small pieces. Further, when the degree of adhesion of the screed to the base is already clear, it is possible to increase the speed and break off in large pieces. Intuitively everything will be clear. When working, always take a stable body position and hold the tool with only two hands. It is not necessary to press hard on the puncher or jackhammer, this does not affect the force from the blow, but the hands will get tired faster.
• It is better to remove pieces of a broken screed immediately with shovels, load them into strong bags and take them out to a certain place for subsequent removal. This is another argument in favor of the need for helpers.

• Breaks are required during work. This is necessary both for resting the hands and for cooling the instrument. After 15 minutes of work - rest 5 minutes. And it is also desirable that their operators also change behind the perforator or jackhammer. But this can only be done if others have good skills in working with the instrument.
• If the old screed is reinforced with wire mesh, then before dismantling with a grinder with a stone-cutting disc, cuts must be made to a depth that would ensure cutting of the reinforcing mesh. The work of the grinder must be combined with the work of a vacuum cleaner, since there were a lot from cutting concrete. The surface is “shredded” into rectangles, such that it is convenient to carry them away in bags, and only then chiselling is performed.
• Those places where pipes or hidden wiring pass a large puncher or jackhammer should bypass. In these areas, then after the "heavy artillery" it is better to let a small hammer drill or even a hand chisel and hammer work. And you also need to be careful in the corners and near the partitions, especially if they are made of drywall or cellular concrete.
• After dismantling and removing all debris, the surface of the base is cleaned with a perforator with a wide spatula from the remnants of the old screed. Then the room is swept, the floor and air are sprayed with water from the sprayer and 15-20 minutes are given for all the dust to settle. The vacuum cleaner removes the remaining dirt.

Prices for polystyrene concrete

polystyrene concrete

It happens that after dismantling the screed, a “cultural layer” with ceramic tiles laid on the floor is exposed. And it happens that this tile was laid back in the 50-60s of the last century. On construction and repair forums, the question often arises of what to do with this tile? Repulse her or not? Opinions on this issue vary. Our opinion is unequivocal - beat off!

The tile, laid in the days of developed socialism in the USSR, has two extremes when it is dismantled. Either she literally "jumps" from the base herself, or "stands to the last." And It happens that tiles behave differently in one area. And all because before there were no tile adhesives with predictable properties in the arsenal of masters. Therefore, they glued who on what much. Just cement was used, and cement with PVA, and Bustilat glue, and even epoxy resin and some other "brutal" compounds with ammonia. Moreover, they were glued without any mineral base in the form of sand, chalk or lime. Therefore, dismantling old tiles can be a problem.

Some home craftsmen mistakenly believe that the stronger the impact of the perforator, the more likely the tile will lag behind the base. However, practice shows that a small hammer with a sharp blade can handle old tiles better than a "monster" but with a more blunt blade. That is, when dismantling an old tiled coating, it is not the strength that is more important, but the place of its application.

After dismantling the old screed and thorough cleaning, preparing the surface for a new screed will be practically no different from what will be described in the next chapter.

The basis of the screed is a concrete slab

It is most pleasant to make a screed on such a surface when you do not have to do earthworks or dismantle old coatings. Nevertheless, the surface must be prepared. What steps should surface preparation include?

• First of all, it is necessary to provide the workplace with good lighting, in which the slightest surface flaws will be visible.
• All joints of reinforced concrete slabs (if any) are cleaned, processed, and then sealed with a cement-sand mortar of the same formulation that will be used for the future screed. And also with this solution, you can close up the junction of walls and floors, in which there may be gaps.
• All dried mortar splashes, lime and others on the surface, as well as everything that lends itself to a spatula and a hammer, is beaten off and cleaned.
• If there are large depressions on the upper surface of the plates, then they can also be smeared with the same solution as the joints between the plates.
• If there are cracks, they are cut to a width of at least 5 mm, and then filled with special repair compounds for concrete.

• After all the solutions have dried, the room is thoroughly cleaned, and then a deep penetration primer is applied with a roller. After the first layer has dried, the second one is applied. Primer treatment is mandatory in any case, even if a screed is made on the separating layer.
• If the screed is bound, then a special compound is recommended for use - Betonkontakt, which incorporates a complex of polymers, cement and quartz sand. After treatment with this primer, the surface becomes rough, to which all building materials “stick with pleasure”. However, we advise you to apply " Betonkontakt"After setting up the beacons, in order to exclude damage to the surface created by this soil.

• If the screed is with a separating layer, then a dense polyethylene film is laid on the floor. The joint of the strips should be with an overlap of at least 100 mm, and the entrance to the walls should be the thickness of the future screed plus 20 mm.
• A damper tape is glued to the walls along the perimeter of the room, which serves to compensate for thermal expansion.

At this stage, the preliminary preparation of the surface can be considered completed.

Prices for "Betonkontakt"

betonkontakt

Setting beacons for floor screed

The floor surface intended for screeding is rarely completely flat. In addition to the unevenness of the relief and the profile of the floor slabs themselves, in most cases the rough surface has a slope in one direction. If in a separate room a slope of 3 mm per 1 meter is imperceptible, then on the scale of the house it can already turn into several centimeters, which is unacceptable. It is always necessary to ensure that the floor in the entire apartment or floor of a private house is on the same level. The exception is bathrooms, which should be 15-20 mm lower. Therefore, with proper repairs, it cannot be that in each individual room the screed is made only in its interests. In no case! You can make a screed in a room, but taking into account the whole apartment or the whole house.

In order for the floor level in an apartment or house not to “dance” as it pleases, it is necessary to beat off the zero level in all rooms. It is very easy to do this if you have a laser plane builder at your disposal, which has long ceased to be a luxury. Let's describe the methodology.

• In a certain place, a laser level is installed on a tripod so that it can capture the maximum number of rooms with its beam. It is better to install it at a height that is comfortable for work - about 140-150 cm. On the walls of the premises, marks of the position of the beam are made with a marker.

• The level is transferred to some room where there is already a mark and is set on her . Further, the position of this label is transferred to all walls. With the help of a masking cord, a horizontal base line is beaten off.
• Similar actions are carried out in all rooms. As a result, it should turn out that a horizontal base line is drawn on all the walls, relative to which the floor level and the thickness of the screed will be calculated.
• Measurement points are marked on the baseline with a certain frequency (1.5-2 meters). Then the distance from the measurement points to the floor level is measured vertically and written with a marker or pencil directly on the wall.

• The minimum and maximum distance from the baseline to the floor surface is found. In the example shown, the minimum distance is 1420 mm and the maximum distance is 1445 mm. The height difference is 25 mm.
• For example, the recommended minimum screed thickness for sand concrete of any brand is 30 mm. This means that from the highest point it is necessary to set aside 30 mm and get that the zero level will be 1420 - 30 = 1390 mm from the baseline. The thickness of the screed in this case will vary from 30 mm to 55 mm. This is perfectly acceptable.

These calculations are very appropriate to put on the plan of the house. Such a document will be very useful in the future, since the screed is usually not done immediately in the entire apartment or floor of the house, but gradually, moving from one room to another.

It's time to learn how to properly arrange beacons. These actions cannot be called heavy physical labor, but a lot depends on the correct placement of beacons. It is they who set the floor surface and from the slightest mistake all further work can lead, at worst, to further elimination of shortcomings, and at best, to banal overexpenditure of the dry mix from which the screed solution will be prepared.

Let's take an example. Let's say there is an apartment of 100 m² in which you need. For this, sand concrete M 300 will be used, in which the minimum layer size is 30 mm. When beating the zero level, it turned out that the thickness of the screed can be from 30 mm to 55 mm (we gave this example earlier). This means that the average thickness of the screed will be approximately (30 + 55) / 2 = 42.5 mm or 4.25 cm. The average consumption of sand concrete M 300 is 20 kg per 1 cm of thickness and an area of ​​1 m². It turns out that there will be an expense for the whole apartment: 4.25 * 100 * 20 \u003d 8500 kg of dry mix, which will be 212.5 bags of 40 kg.

Now imagine that when installing beacons, the master, instead of the minimum 3 cm at the highest point, set 4 cm with an “iron” argument “the pocket does not pull the stock”. We recalculate: an extra 1 cm added to the screed over the entire area of ​​100 m² will result in 20 * 100 \u003d 2000 kg, which will be an additional 50 bags in 40 kg bags. It turns out that the stock still "pulled the pocket." And the point here is not so much about money, but about the extra load on the floor. The extra 2 tons will lie on the base of the floor. The extra 2 tons will have to be dragged to prepare the mortar and lay it down.

All readers probably know that the most inconvenient load during transportation and especially lifting to the floors is a piano. Loaders shy away from it "like fire" and calculate at a special rate. The average weight of one piano is 250 kg. It turns out that plus 1 cm of the tie in the considered example is equal in weight to approximately 8 conventional pianos or one conventional Lexus RX 400 SUV.

There are too many ways to set up beacons to describe them all in one article. Each master has his own favorite way, which does not have to be similar to others. In principle, what's the difference if, with different methods of setting beacons, two masters get equally good results. We propose to consider a method that will be understandable to everyone and even a beginner can reproduce it.

Completely different objects and devices are used as beacons for floor screed. Someone prefers to make lighthouses from a solution, someone uses pipe segments. The ceiling guide profile is very widely used, " borrowed» in drywall systems, which we know as PN 28*27 or UD 28*27. Its shape and sufficient rigidity allow it to be used for lighthouses. For example, as it is done in the figure.

In the method of placing beacons we are describing, we will use the PM-10 beacon profile, originally conceived for plaster, but successfully used in screeds. It is made of galvanized sheet steel and has a shape that also provides it with good rigidity. The side shelves of PM-10 are perforated to facilitate its attachment to the leveling surface in various ways.

Very often beacon profiles are fixed with mortars. To do this, on a pre-marked line, on which the lighthouse should be located, at the beginning and at the end of it, self-tapping screws are screwed into the previously installed dowels. Then, using a laser level or other measuring tool, the self-tapping screws are set so that their upper plane is in the plane of the future screed. Along the line of the beacon, with a certain frequency, slides are made of cement-sand or other mortar, and then the beacon profile is placed on them and pressed in with a rule that is pressed against the caps of the self-tapping screws.

When the beacon profile is pressed into the mortar pad, make sure that it is pressed against the rule along its entire length. Excess protruding above the lighthouse is cleaned. When the solution dries, you can begin the main work on the screed. For a cement-sand mortar, at least 1-2 days must pass for the lighthouse to be fixed, therefore, to speed up the process, some craftsmen use adhesive gypsum mortars or even alabaster. The beacon in this case is fixed almost instantly and work on laying the screed can be started immediately. Everything seems to be fine, but it turns out that there will be foreign inclusions from other materials in the body of the screed. During the operation of the screed, in those places where there are “strangers”, cracks will most likely form, since the coefficients of linear thermal expansion for different materials are different. Therefore, beacons should be installed only on the solution with which the screed will be made.

The method of installing beacons on the solution has a major drawback - it is the impossibility of correcting the position in case of an error. Only the dismantling of the beacon and re-assembly can correct the situation. Therefore, it is better to use a method that will allow you to easily mount, dismantle the beacon and adjust its position. This is easily implemented using self-tapping screws with dowels and a special fastener - a plastic clip for fastening beacons.

This clip consists of two parts - the clip itself and the lock that fixes the beacon. This type of fastening of the beacon is good because the clip itself can be mounted on the head of the self-tapping screw after it is screwed in and adjusted in height. For this there is a special groove. Then, already after the beacon is put into the clip, the final fixation with the lock is in progress. It turns out a very reliable mount, which can still be adjusted in height. The price for such clips is cheap - 100 pieces cost 250-300 rubles.

Consider the process placing beacons with plastic clips. For convenience of perception, we present it in the form of a table.

Image	Process description
	On the prepared floor surface, the position of the beacons is marked, which should be installed in the direction of pouring the screed from the far wall of the room to the front door parallel to the side walls (if the room is rectangular). From the side walls, to the guides closest to them, an interval of 200-300 mm should be maintained. The distance between neighboring beacons is 1-1.5 meters. The rule laid down for neighboring beacons must still have a margin of at least 200 mm on both sides.
	On the position lines of the beacons, with an interval of 500 mm, holes are drilled with a perforator, into which dowels are immediately hammered.
	In the room where the beacons are placed, there is the highest point, according to previously made calculations. At the corresponding point, the dowel is screwed in, but not completely. The laser level is set and set according to the baseline previously drawn on the walls.
	On a straight wooden block, a mark is made on the position of the screw head relative to the baseline, but taking into account the height of the beacon (10 mm) and the clip (2 mm). That is, 12 mm is added to the previously calculated screed level relative to the baseline. The bar is installed vertically on the head of the screw and the position of the mark is controlled.
	By screwing or unscrewing the self-tapping screw with a screwdriver, the mark on the bar and the laser level beam are matched. The self-tapping screw at this point can be considered set, and all the rest must be set on the same level with it.
	The laser level is installed on the floor and its beam should be above the cap of the exposed screw. A long bit is clamped into a screwdriver. Then the bit is inserted vertically into the slots of the exposed self-tapping screw and it is controlled that the laser beam is on it.
	A strip of white masking tape is glued onto the bit in a circle, then it is again placed vertically in the slots of the self-tapping screw and the position of the laser beam is marked with a marker.
	Self-tapping screws are baited into all previously mounted dowels.
	A screwdriver sequentially tightens all the screws to the level determined by the mark on the bit and the laser beam.
	Clips are put on the heads of the self-tapping screws, and the neighboring ones should be oriented opposite to each other.
	The position of the clips is checked with a rule, a level and a laser beam. The rule must lie on all clips strictly horizontally.
	Beacon profiles are inserted into the grooves of the clips. All profile joints should fall only on clips.
	Profiles in clips are fixed with latches.
	The room is cleaned with a vacuum cleaner.
	The surface of the floor is primed with a deep penetration compound.
	After the primer dries, a semi-dry sand concrete solution is mixed and all beacons are reinforced with it. The same solution can fix the position of the damper tape.

The proposed method is also good in that the level can be set without the beacons themselves, and they can be put on immediately before laying the solution. This is very useful when the screed is being reinforced.

Floor screed reinforcement

The question often arises about the advisability of reinforcing the screed, because by its purpose it is often not a power element that carries the main load. And partly this is true. But the absence of reinforcement can only be justified in bonded screeds laid on a reliable concrete base, and in all other cases it will not be superfluous. Consider cases where reinforcement is required.

• Screeds in the underfloor heating system are necessarily reinforced, as they are subject to thermal expansion and contraction.
• Floating screeds laid on insulation boards are also necessarily reinforced, since it has a much lower bearing capacity.
• Ground screeds must be reinforced with reinforcement, as they are usually laid on a loose base. Another reason for reinforcement may be external factors, such as seasonal swelling.
• If heavy objects are installed in the room or the screed is subject to any dynamic loads, then reinforcement is mandatory.
• Screeds with a height of more than 5 cm are reinforced to avoid cracking during the drying process.

For reinforcement, various materials can be used. Let's consider what.

Reinforcement of the screed with metal meshes

The oldest proven method of reinforcing screeds is steel mesh from reinforcement or wire. the former are used for power heavily loaded floors on the ground, for example, in garages, and the latter in all other cases. Grids for reinforcing screeds are made of VR-1 wire with a diameter of 2.5 mm to 6 mm. If earlier a frame was formed using a thin wire, which twisted the stacked rods, now meshes are offered, connected by spot welding. Cells can be square or rectangular, ranging in size from 50 to 200 mm. Obviously, the smaller the cell size and the thicker the wire, the more reliable the tie will be. Grids made of thin wire (up to 3 mm in diameter) can be sold in rolls, and thicker ones in the form of cards 0.5 * 2, 1 * 2 and 2 * 3 meters in size.

A very important element in any wire mesh is the presence of notches on the bars, located in increments of 2-3 mm along the entire length. They significantly increase the area of ​​adhesion of the frame to the concrete solution, which strengthens the finished screed. When buying wire mesh, you must strictly ensure that all wire intersections are welded, as not all manufacturers do this. And it is also worth checking the grids for the absence of strong foci of corrosion, which will expand in a highly alkaline concrete solution when it hardens.

There are a lot of sources on the Internet that tell how to “correctly” reinforce a floating screed with underfloor heating pipes. A wire mesh is placed on a layer of heat and waterproofing, and only then pipes of a warm floor are attached to it with plastic clamps. The deeds of such "craftsmen" can be seen in the photograph.

Such "reinforcement" is inherently possible - it is hiding expensive wire mesh under a layer of concrete. They do not perform any reinforcing function, since they will simply “roll” under the screed. In order for the reinforcement not to be useless, the meshes must be inside the concrete, while they must be separated from the base on a protective layer with a thickness of at least 15-20 mm. In thin screeds, the mesh will be located approximately in the middle, and in thick screeds it is better to place it in the lower third, so it will work better under various loads that occur.

When forming screed frame made of steel meshes be sure to overlap by 1 cell, but not less than 10 cm. For example, if a grid with a cell of 10 * 10 cm is used, then adjacent canvases should overlap exactly by 1 cell, and if 20 * 20 cm, then half of it is enough . In order for the grid to stand at the same distance from the base, several methods are used:

• The grid is installed on the slides from the cement mortar - exactly the same as the screed will be poured. Sometimes this is combined with the installation of beacons. This is a perfectly acceptable method, but its main drawback is the non-simultaneous drying of the slides and the screed itself. This can lead to heterogeneity of its structure and delamination. The use of gypsum solutions is unacceptable!
• The reinforcing mesh is installed on supports made of pieces of broken brick, fragments of concrete or other improvised materials. This method is also allowed, but it is quite difficult to set the grid at the same distance from the base. And further, when the screed is laid and moved along the grid, some homemade supports may fly out. The use of wooden blocks is unacceptable, as they will increase in volume from the water and “tear” the screed.
• The most modern and best way to install reinforcing meshes is to use special reinforcement retainers. They are made of plastic, have calibrated dimensions and are selected for any type of reinforcing mesh, for any thickness of the protective layer and for any base. Such “implanted” racks do not in the least affect the concrete or cement-sand structure of the screed for the worse. These products can be easily found in any normal building materials store or market. The price for them is cheap: about 0.8-1.6 rubles per 1 piece, if you take packages of 1000 pieces. For 1 m², it is recommended to use at least 8-12 clamps. It depends on the diameter of the reinforcement or wire, the mesh pitch and the base material.

Reinforcement clamps - a modern and best solution for installing reinforcing meshes

The most common reason why screed reinforcement is necessary in residential premises is a warm water floor. But placing a metal mesh on the base, and then attaching pipes to it, is a rather dubious task. The effectiveness of such "reinforcement" is close to zero. The most correct thing is to fasten the pipes to the thermal insulation, and on top of them already place steel meshes on the reinforcement clamps.

We note the advantages of using steel reinforcing mesh for screed:

• Such ties have the highest strength: tensile strength, bending, for stretching and compression.
• Excellent resistance to temperature extremes over a very wide range.
• Steel grids laid on top of underfloor heating pipes make it possible to distribute temperature gradients more evenly, since metal has a thermal conductivity many times greater than concrete.
• Properly mounted screeds with steel reinforcing elements have a long service life.

There are few disadvantages of steel reinforcement - this is a high price and the ability to corrode if stored and installed improperly.

Reinforcement of the screed with polymer and composite elements

Progress does not stand still, so to replace traditional reinforcing steel elements others come from various polymers or composite materials. For a long time there was no alternative to traditional steel reinforcement, but now a worthy “rival” has appeared - reinforcement and meshes made of polymer and composite materials. Let's briefly consider them and immediately note the advantages and disadvantages.

Composite rebars are bars of various diameters, which may have ribs similar to those found on steel rebar, or be coated with sand for better adhesion. The rods are formed from fibers and a polymer binder, which is why such reinforcement is called composite. Fibers use glass, basalt or carbon and therefore the reinforcement is called fiberglass, basalt-plastic or carbon fiber.

Composite reinforcement has a number of advantages, we list them:

We note the disadvantages of composite reinforcement:

• Lower stiffness of composite reinforcement than steel.
• Lack of plasticity - high brittleness.
• The heat resistance of composite reinforcement is worse. Fiberglass loses its properties at 150 °C, carbon fiber at 300 °C, and steel only at 500 °C.
• When cutting composite reinforcement, a large amount of dust harmful to health is generated. This is especially true for fiberglass reinforcement.

Work with composite reinforcement in the same way as metal. When knitting frames, wire or plastic clamps are also used, and for installation, clamps or mortar cushions. The correspondence between the diameters of steel and fiberglass reinforcement can be seen in the following table. At the price of composite reinforcement is not lower than traditional steel, however, if there are large logistics costs for delivery to the site, then in the end its use can be cheaper. True, when mounting the frame and pouring the screed, care must be taken, because composite reinforcement is much easier to break than steel reinforcement, since it works much worse for bending.

Prices for fiberglass reinforcement

fiberglass reinforcement

Plastic meshes are now widely used to reinforce screeds located on reliable foundations. They are made of polypropylene or fiberglass with a special impregnation that prevents the effects of an alkaline environment inside the concrete. Grids are produced in a very wide range, with different mesh sizes. For screeds, polypropylene meshes with a mesh size of 35 to 50 mm are most commonly used. The width of the canvas is from 50 cm to 4 meters, and the length of the mesh roll is from 10 to 50 meters. Of course, it is very convenient. We note the advantages of plastic mesh for reinforcing the floor screed.

The only drawback of plastic nets is the impossibility of their use in rough screeds on the ground.

Fiber screed reinforcement

The reinforcement of the screed with microfibers (fiber) differs from all the others in that the frame itself is not visible. But the reinforcement in the concrete mixture is still in the form of thin fibers, evenly distributed in the solution, and after drying, in the thickness of the screed. It is they who reinforce the concrete in all planes, as they are randomly located. Their addition, even in small quantities, significantly increases the brand of concrete, impact resistance and strength. in fiber concrete (this is what concrete with the addition of fiber is called) there is also an almost complete absence of shrinkage cracks. Fiber can be made from different materials:

• Steel fiber - is a piece of high-quality steel wire with a diameter of 0.2-1.2 mm and a length of 25-60 mm. For better adhesion to concrete, the ends of the wires are curved. Steel fiber is the strongest, but is not used in screeds. Its purpose is concrete for massive monolithic structures, mainly prefabricated.

• Fiberglass fiber - significantly improves the quality of concrete, which allows you to reduce the amount of cement up to 15%, and water - up to 20%. It is not used in monolithic structures and screeds, since fibers from a special alkali resistant zirconia glass is very expensive. Therefore, fiberglass fiber has found his application in decorative and structural plasters.
• Basalt fiber is a piece of basalt fiber with a diameter of 20 to 500 microns and a length of 1 to 150 mm. Reinforcement of concrete with basalt fiber increases its strength by 4-5 times, abrasion resistance - by 2-3 times, tensile strength - by 2-3 times, compressive strength - by 1.5-2 times, water resistance - by 2 times. This type of fiber can partially dissolve in the cement mortar, but from this it only gains strength. It turns out that reinforcement occurs both chemically and mechanically. Consumption - approximately 0.8-1.2 kg per 1 m³ of ready-made concrete solution.

• Polypropylene fiber is the most common a type of micro-reinforcement of floor screeds, since along with the excellent characteristics of concrete (almost like with basalt fiber), its prices are lower. Polypropylene fiber does not enter into a chemical reaction with concrete mortar and does not change its properties during the entire service life of concrete. The consumption of polypropylene fiber is approximately 0.6-1 kg per 1 m³ of the finished solution.

Adding fiber to concrete mortar is very simple, there are two ways to do this - dry and wet. All types of fiber, except for basalt, can be kneaded in a dry way. This means that the basalt fiber is first soaked in water, and then the dry ingredients of the mixture are added. Steel fiber is added only in a dry way. That is, it is added to the sand, mixed, then cement is added, and then water.

It should be noted that the mixing of solutions with fiber will be of high quality only when it is done mechanically - using concrete mixer or mixer. The mixing time with the fiber must be increased by at least 30% so that it is as evenly distributed throughout the volume as possible.

Conclusions about the reinforcement of the floor screed

The opinion of the authors of the article about reinforcement is unequivocal - it is necessary in any case in one form or another. This is based primarily on personal experience, but also on the analysis of the opinions of professionals in numerous thematic construction forums. Here are the arguments:

• Any properly made reinforcement makes the screed better.
• Highly loaded screeds, as well as those made on the ground, must be reinforced with a reinforcing cage.
• Composite rebar offers no advantage over steel rebar at current prices.
• Any reinforcing frame must be inside the screed, and the thickness of the protective layer must be from 15 mm.
• on a reliable basis, it is sufficient to use a polypropylene reinforcing mesh.
• Reinforcement with polypropylene or basalt fiber is always best done, since the cost of this is disproportionately less than for all other components of the solution, and the result, if used correctly, is obvious.

Preparation of floor screed mortar

The question of the correct preparation of the solution in the arrangement of the floor screed is extremely important, since both the quality of the installation and the period of further operation depend on it. If you “rewind” 20-30 years ago, then there were no issues with this at the construction sites of private houses in the territory of the former USSR. Either just on the floor surface, or in makeshift troughs, a solution consisting of cement, sand and water was kneaded with shovels, and then it was laid on the floor surface using wooden graters, slats, pieces of edged boards and other improvised means. And a lot of screeds, made then, are still serving. But this does not mean that we should continue to use these "grandfather" methods.

Modern screeds are often made on a layer of insulation, and warm floors are also no longer a luxury item. Accordingly, the requirements for which solution should be prepared also increase. We will immediately tell readers that mixing with shovels on the floor or in a trough, which some current sources can even talk about, is an outdated approach. A good screed should have a uniform structure, so the preparation of a solution for it is better compared with the craft of a pharmacist, which from various containerswith the help of beakers accurately measures the right amount of ingredients, and then mixes them until smooth. It is clear that the volumes of the pharmacist and the builder are different, but the ratio should be similar. And, of course, the preparation of the solution should be carried out only using mechanisms - mixers or concrete mixers (concrete mixers).

A drill mixer is a very useful device that will come in handy in the household more than once.

Floor screed solutions can be prepared in two ways, each with its own advantages and disadvantages.

• The first way is self-preparation of the solution. At the same time, the necessary ingredients are purchased in the right volume, which are mixed in certain proportions. It should be noted that experience or clear instructions are desirable with this method, not to mention the quality of the individual components of the solution.
• The second method is the use of ready-made dry building mixes, which are specially designed for floor screed. This simplifies the work, but costs more.

Let's consider these methods separately and in more detail.

Self-preparation of floor screed mortar

Modern SNiPs do not in the least interfere with self-preparation of the solution, but its grade must be no less than M -150, which means that each square centimeter of the screed must withstand a load of 150 kg. This is sufficient for simple screeds, but may not be enough for underfloor heating. In addition to the traditional screed components - cement and sand, it is also recommended to use a special additive - plasticizer . What does it give?

• In order for cement to turn into stone, it needs a certain amount of water, approximately equal to a quarter of its mass. Approximately 25 liters of water are needed for 100 kg of cement. But such a ratio will not allow to obtain a plastic and fluid solution of cement with fillers, therefore, an additional amount of water is introduced into the mixture, which makes it possible to conveniently lay the solution. Plasticizers allow you to minimize the water-cement ratio, which has a beneficial effect on both the rate of hardening and the final strength of the structure or coating.

Plasticizers are not a luxury, but a necessity

• The use of a plasticizer avoids the appearance of air bubbles in the body of the screed. This is especially true in the pouring of underfloor heating screeds. When laying the screed, due to the plasticity of the solution, the air freely exits itself, and the cement-sand mortar better “encloses” the underfloor heating pipeline.
• The grade strength of the finished solution when using a plasticizer increases by 20-40%.
• Solutions with a plasticizer have frost resistance 50% higher than without it.
• The “life” time of the solution, in which it can be worked with when laying the screed, increases significantly. This allows you to make batches in a large volume and increase productivity.
• The water resistance of screeds with a plasticizer is significantly higher than without it.

We hope that we have convinced our readers of the need to use a plasticizer for screed. It can be easily found on sale in liquid or powdered form. It can be called differently, but according to its chemical composition and in fact in 99% of cases it is a C-3 plasticizer. measured volume of water. All instructions for the use of the plasticizer are always indicated on the packages.

Now let's look at how to prepare a time-tested screed solution.

• Portland cement must be used as a binder. widespread brand M 400. You can also use M 500, then the screed will be even stronger. Usually it is sold packaged in 50 kg bags, but for ease of transportation there are bags of 25 kg. Of course, it is necessary to check that the expiration date of the cement has not been exceeded.

• As a filler, it is recommended to use quarry sand, in which grains of sand have an irregular shape with sharp edges. In a screed, such sand will adhere well by itself. with you, with cement and foundation. River sand with prolonged exposure to water takes on a smoother shape, which means it will more readily peel off the screed.
• Water for the preparation of the solution should be used only clean, free of impurities of oil products, fats and other contaminants. Naturally, water containers should also be clean and intended only for her. It should be noted that the required amount of water does not need to be added immediately, since a solution with a very high content of it can be obtained. This will have a bad effect on the convenience of laying and the strength of the screed. The sand may already contain some water and the use of a plasticizer also greatly affects the water/cement ratio.

Now about the proportions of the ingredients of the screed solution. The “classic” proven over the years is one part cement to three parts sand. We propose to calculate the exact amount using a calculator.

Floor screed mortar ingredient calculator

The proposed calculator is very easy to use, requires a minimum amount of initial data, and produces results with good accuracy. The only explanation for its use is the paragraph on the height difference of the screed. This is nothing but the difference between the highest point of the base and the lowest, expressed in millimeters. We talked about this in our article when we considered the installation of beacons.

In order for the laminate or linoleum to lie perfectly even, the base for them should be made as smooth as possible, for which you need to study how the finishing professional flooring is done, the construction instructions for which are described in detail below. Why it is preferable to do it yourself is pretty obvious. After all, this will mean considerable savings in funds (which would otherwise be spent on paying for the work of the masters) and the acquisition of a fair amount of experience.

Of course, the process of filling the floor can be entrusted to specialists. But many tend to perform and control everything on their own. The first thing to do before you start work is to prepare all the necessary tools, as well as inventory, which are required by the floor screed technology in the apartment.

Required Tools

By priority of application, you will need: a hydraulic level, a pencil, a chopping thread, a tape measure. Also make sure that you have a cord, knitting wire, a clerical knife, wire cutters, a puncher and a screwdriver, a rule, a trowel and a grater, as well as a shovel at hand. Some of the work will be easier to do with rubber boots, which should be considered in advance.

It is logical that, without building materials, the screed can only be made dry, poured using the old-fashioned method of clay, which can be dug up behind the house, and then covered with shields. However, this is not the best way out, so we stock up on the necessary amount of cement and sand. We calculate the flow rate of the mixture by multiplying a square meter (in centimeters) by the height of the fill, using the standard volume formula. One share of the figure received is cement, for 50 kilograms of which 15 liters of water are required, and another 4 parts are sand. For elasticity, as a plasticizer for underfloor heating screed, 100-150 grams of liquid soap is added.

Add liquid soap for elasticity

And finally, the process itself. The role of the screed is not only to level the floor, it is necessary both to hide the underfloor heating pipes and to create an additional layer of insulation or sound insulation in combination with a hydrobarrier. There are different ones, and if you want to get a heat source by hiding pipes in the thickness of cement, in this case a floating one will be used. Simply put, it will not lie on a rigid base of the ceiling, but on a rather soft layer of thermal insulation (we take expanded polystyrene plates with sufficient hardness), on top of which the pipes will be located.

The website site masters have prepared a special calculator for you. You can easily calculate the required amount of cement.

How to make a floor screed - a sequence of actions

The first and main process is the measurement of the premises, and not the purchase of building materials, because while you do not know the scope of work, you do not know how much cement or sand will be needed. There are many stages of work ahead, and only after taking the first step, you will know with what numbers to go for the screed components.

Master class floor screed - step by step diagram

Step 1: Defining the Horizon and Fill Level

When the preparation for the floor screed is completed, with the help of a hydraulic level we find the horizon at a height of 1.5 meters, and with a chopping thread covered with chalk, we make marking lines.

Then we measure the distance to the base with a tape measure and find the point farthest from it and closest to it, thereby determining the difference in levels in the room

Based on the measurements, you can calculate how to properly fill the floor screed, as well as the amount of materials that will be required for it. is 40 millimeters. We complete the marking work by transferring the markers down the corners to the fill level and beating off the new lines with a thread, along which the new base surface will pass.

Step 2: Preparing the base

The next stage - preparing the floor for a screed, will not require much labor if it is planned to make a heating system in the room under the finish coating.

The role of the substrate in this case will be assigned to the insulation, separated from the floor slab by film waterproofing. A reinforcing mesh is laid on top, and on it are metal-plastic or propylene pipes bent according to a certain pattern (snake or spiral), fixed with special fasteners. If the underfloor heating screed for a film electric heater is planned to be poured directly onto the ceiling, it must be thoroughly cleaned and even washed.

Step 3: Installing beacons by level

Having achieved an acceptable state of the base or substrate from a heater with heating elements, it's time to move on to installing beacons, without which it is impossible to install a screed under a warm floor. To do this, we drive dowels into two opposing walls along the line of the future screed after 1-1.5 meters, to which we tie a cord (you can use nylon).

Exactly along the strings stretched in the same plane, raising and lowering with the help of wooden wedges, we place parallel beacons from a metal profile 20x40 millimeters at regular intervals (two at a distance of half a meter from the walls).

They are necessary so that subsequently a screed under a warm floor is equal to them.

Step 4: Fixing the beacons and installing a thermal seam

Since in the process of laying the mortar, the beacons can move and change their position in space, they should be carefully fixed. Holes are drilled in the ceiling, into which a pair of screws is screwed on both sides of the profile, at a short distance from each end of the pipe and in the middle.

Then the tie wire is wound around the screws so that the beacon is firmly fixed in place.

It remains only to make a thermal seam along the perimeter of the room, fixing the belt from the remnants of the insulation along the lower edge of the walls with liquid nails.

Step 5: Mixing the Mortar

So, beacons are placed around the room, the thermal seam is securely fixed, it's time to start making the floor screed. For the solution, we take 50-kilogram bags of cement grade 400, no less, sand is sold by weight or by cubic meters, for work it will need 4 times more. Accordingly, in a large container, which can serve as an old bath (it is better to use a compact mobile concrete mixer), we mix cement with sand in proportions of 1: 4; when the composition becomes homogeneous, add water. The consistency should be like thick sour cream.

When adding a plasticizer, care should be taken, an overdose leads to a slowdown in the hardening process of the composition.

Step 6: Fill and Level Rule

If you have prepared a water heating system in the form of pipes laid on a heater, laying a warm floor in a screed will not require any special technologies.

We make sure that a small portion of the solution, laid on a flat place, slightly floats, but does not spread like liquid, that is, it corresponds to the proper degree of density. Then we simply fill with the mixture the area between the wall, which is opposite the door, and the second beacon from it (the first one should hide under the solution).

Level the solution with a shovel.

We level the solution

Using the rule, we finally bring the mixture to the level of beacons.

Step 7: The Nuances of Leveling and Removing Voids

For those who are not confident in their abilities, it is advisable to watch in advance in the training video how to properly make a rough floor screed with your own hands, the video will also tell you a simple way to achieve the desired result without flaws.

For example, few beginners know that when working with the rule, it is desirable to level the solution so that it is slightly higher than the beacons, then after shrinkage it will become flush with them. In the presence of a heating system, it is possible to perform a floor screed without voids using an extremely simple method - it is enough to slightly support the reinforcing mesh so that the mixture covers it and the pipes from all sides.

Step 8: Rule Leveling After Curing

When the cement mortar covers the entire area of ​​\u200b\u200bthe room, you have to work as a rule, walking directly on the liquid mixture, for which, in fact, you need to prepare rubber boots before laying the screed on the floor.

Then it remains only to wait for the fill to harden enough so that it can be moved around. As a rule, the drying time of the floor screed takes at least two weeks, during which you need to regularly moisten the surface with water every other day. After the cement has hardened, you should take the rule and scrape off the top layer to the beacons, collecting the excess in a bucket.

Step 9: Removing Beacons From Cured Cement

How the floor screed device is completed, the video will tell you best, but there is nothing complicated about it, and often only instructions are enough. After the surface has become smoother, and the beacons have appeared from under the mortar layer, we take a spatula and carefully cut through the thickness of the fill on both sides of the profiles.

Then we bite the binding wire with wire cutters and remove the pipes, tapping them with a hammer in the process to avoid lifting the stuck layers.

Pipe extraction surface

To do this, add a little fresh cement and water to the scraped mortar, which is placed in a bucket, mix thoroughly and fill the grooves from the profile pipes with the mixture.

When the remnants of the cement-sand mixture are removed, we only have to grout the floor screed.

It is done with a grater and water. We start from the far corner of the room, slightly wetting the filling with water and carefully smoothing the surface with a grater.

After the end of the "polishing", when the base takes the proper form that you wanted, cut off the excess of the thermal seam flush with the surface with a clerical knife, the rest will subsequently be hidden under the baseboards. Now the work is successfully completed, and you can move on to the next room.

An uneven floor can spoil the appearance of the room, lead to split tiles, warp linoleum, reduce the life of the laminate. Therefore, to level the surface, before laying the floor covering, a dry screed is used. Screed - an intermediate layer between the finishing coating and the base of the floor. The service life of the floor depends on the quality of the screed. Screeds exist solid monolithic (seamless or they are also called "self-leveling floor") and prefabricated (dry).

Screed - an intermediate layer between the finishing coating and the base of the floor

Purpose of the screed

In addition to the main function - alignment, the screed performs several others:

• strengthening the concrete base;
• increasing the heat and hydro-noise insulation of the room;
• hiding wiring and pipes located on the floor;
• load distribution during floor operation;
• providing the necessary slope for water flow in the bathroom, kitchen;
• rise to the desired level of the subfloor.

Screed Requirements

The screed used must meet certain requirements:

• thickness of at least 20 mm - when using a polymer-cement mixture with reinforcing fibers, 30 mm - cement-sand mortar, 40 mm - if there is an insulating layer under the screed;
• when laying the screed on soundproofing, leave 20-50 mm from the wall (fill this space with soundproofing material);
• when laying the screed on pipes, its thickness should be 15-20 mm more than the diameter of the pipe;
• the density of the mixture should be the same around the entire perimeter;
• the strength index must be at least 15 MPa (20 MPa when using polyurethane material);
• when using liquid mixtures, it is necessary to use a waterproofing barrier;
• with a screed thickness of more than 50 mm, to prevent splitting and increase strength, reinforcement is recommended.

The density of the mixture should be the same around the perimeter

Types of mixtures

There are 2 types of mixtures for floor screed:

• Self leveling

The finished mixture is applied in a thin layer (20-30 mm). During application, it itself evenly spreads over the surface of the floor. Can be used for any type of coverage.

• Requiring leveling with a spatula

They are used for severe unevenness on the floor surface, the need to create a slope or the manufacture of a warm floor.

Self-levelling floor screed

Classification of screeds according to the type of materials used:

• Wet

It is the most common, inexpensive method of screeding. The composition includes cement, sand and water. With its help, you can level the floor surface even with significant defects.

It takes a long time to dry such a solution (about 4 weeks), while the coating may crack during drying.

There are several types of liquid mixtures based on cement:

• concrete, contains concrete and fillers (crushed stone, gravel or sand). It is best suited for the primary formation of the base, as it has a large fraction and helps to level any surfaces;
• cement-sand mortar is similar in composition to a concrete mixture, but it does not contain crushed stone. The absence of this component leads to an increase in price, a decrease in the strength of the screed.
• lightweight concrete contains, instead of the classic filler (crushed stone), granules or crumbs of expanded polystyrene. Such a solution provides good thermal insulation, minimal load on the ceiling, but has less strength;

Wet floor screed

• the polymer-cement ready mixture is used as a final layer (thickness not more than 15 mm), on a flat surface for the subsequent laying of the floor covering. It contains Portland cement, fractional quartz sand, polymer additives. The components included in the composition provide additional strength, reduce the likelihood of precipitation, and contribute to a fine distribution of the mixture.

• Semi-dry

A common type of tie. To prepare the mixture, less water is used, but more sand. Less moisture in the composition causes less strength and faster drying (you can start laying the final coating after 15 days, but put heavy objects only after 4 weeks).

• Dry

Due to the absence of "wet" processes, the use of such a screed allows you to immediately proceed with the installation of the floor covering.

Dry screed knauf (multi-layer construction of gypsum panels) is most popular for leveling floor surfaces. Depending on the purpose, 4 types of knauf screeds are classified:

• "Alpha" - used for floors with a flat surface;
• "Beta" - laying on a flat surface with a substrate of heat-insulating porous materials;

Dry screed Knauf

• "Vega" - installation of the structure on a leveling, dry layer of backfill;
• "Gamma" - laying on a combined substrate.

• self-leveling floor

Thin-layer coating based on liquid-viscous oligomers (liquid rubbers and elastomers). The use of such a coating will not be able to even out significant differences. For this reason, the best option is to apply it in a thin layer on a previously leveled surface.

Types of wet screeds

Depending on the base coat and its operation, there are 4 types of wet screed:

• knitted laying - carried out on floor slabs;
• with waterproofing - the most appropriate use of this screed is in rooms with high humidity or the possibility of a large amount of water getting on the floor (bath, kitchen). The screed mixture is laid on the waterproofing layer;
• with thermal insulation - a screed with reinforcement is laid on a layer of thermal insulation;
• with a final self-leveling coating - for leveling the floor before using floor coverings that are sensitive to minor irregularities (linoleum, laminate).

self-leveling floor

Materials for floor screed in the apartment

What is needed for floor screed in an apartment in addition to the finished mixture or components for its preparation?

To install it, you may need:

• wire, plastic or steel mesh (for installing a reinforcing layer);
• to prevent the appearance of cracks on the screed during its drying;
• sound or heat insulating materials;
• damper tape isolates the walls from contact with the screed solution.

Initially, you need to dismantle the old screed, to prevent the manifestation of its defects on the new base. Remove debris and dust. The presence of cracks or depressions should be filled with concrete mortar. Using a machine, sand the floor surface, get rid of dust, vacuum it. Lay damper tape between wall and floor. If desired, you can install waterproofing with a plastic film or bituminous mastic.

Preparatory work before floor screed

Before laying the screed, it is necessary, at a distance of 1.5-2 m from each other.

The highest point of the floor will correspond to the level of the future screed. If the floor surface is not sufficiently even, to place the beacons on the same level, substrates can be used under them.

With a long building level, check the location of the beacons along the plane. To fix them, use a cement mixture every 30 cm.

Calculation of the number of components for concrete

To calculate the required number of components, it is necessary to calculate the total volume of the mixture. To do this: multiply the average height of the screed by the length and width of the room.

If the floor width is 3 m, the length is 4 m, the lower point of the screed is 3 cm, the upper one is 4 cm, the average height of the screed is (3 + 4) / 2 = 3.5 cm, the required volume is 0.035 m * 3 m (width) * 4 m (length) = 0.42 m3.

Floor marking for screed

To prepare a mortar with a ratio of cement and sand of 1: 3, you need to take 0.105 m3 of cement and 0.315 sand. 1 m3 of cement has a mass of approximately 1500 kg, then its required amount is 0.105 * 1500 = 157.5 kg. 1 m3 of sand - 1400 kg, then its required amount is 0.315 * 1400 = 441 kg.

High quality concrete mortar

To prepare a high-quality solution, it is necessary to mix all the components correctly:

• mix the dry ingredients (sand, cement) well. To do this, it is better to use a drill with a nozzle or a construction mixer;
• add water (1/3 of the weight of cement) and plasticizers to another container (the required amount will be indicated on the package);
• to the liquid component slowly, stirring, add dry. The finished solution will be similar in consistency to thick sour cream.

Concrete screed device

Not everyone knows how to make a floor screed in an apartment on their own. Before starting work, you should read the recommendations:

Concrete screed device

• pouring should start from the far wall of the room;
• pour the solution between the guides, in one go;
• with a large thickness of the screed, reinforce;
• level the mixture towards you until the air is completely released and the voids are filled;
• after 24 hours, remove the guides and fill the space with the mixture.

After laying, it remains only to wait for drying. But ? After 4-5 days it will be possible to walk on the floor. Full drying will be only in a month.

When self-laying the screed in the apartment, you should know:

• must be laid on protected pipes. For these purposes, you can use boards or shields. Pipes leading to the collector must be thermally insulated;
• with a significant unevenness of the floor or its rise by more than 10 cm, an expanded clay concrete screed is suitable. Despite the fact that the laying process is quite laborious, it has good heat and sound insulation characteristics;
• before laying the coating (parquet, laminate), make sure that the screed is completely dry;
• for better drying, drafts should be eliminated in the room, the use of heaters should be excluded;
• before using the laying material (to prevent its damage), place a special gasket on the screed.

It is not difficult to carry out a screed in an apartment. The main thing is to purchase quality materials and follow the instructions.

Concrete and cement floors serve for decades, do not creak and generally do not cause any problems to residents. Of course, if all the work is done technically correctly. Therefore, we offer you a comprehensive manual for pouring floor screed with sand-concrete mixtures for different types of coatings with your own hands.

The essence of leveling the floor with a screed

There are three typical circumstances when the screed becomes almost the only way to arrange an even and reliable base for the subsequent laying of the final floor.

The first option is concrete floors and ceilings with significant irregularities and defects. First of all, this is typical for apartments in panel houses, where the gaps between the “voids” and casting defects do not allow the surface to be used as a subfloor. Cast ceilings can be seriously filled up in the general plane, especially in new buildings. In such cases, the screed is performed by the standard method.

Another thing is if the floor level needs to be raised by 15-20 cm, when pouring concrete is extremely unprofitable financially. A classic example is ground flooring on the first floor. In this case, the screed is poured over the bedding of crushed stone or expanded clay. This is called a screed on the bulk layer, the technology of work has significant differences.

The third option is the most exotic. If the mechanical characteristics of the subfloor do not allow the desired type of coating to be laid, a so-called preparatory screed is poured on top. The most common example is the floors in the bathrooms of wooden houses.

Keep in mind: the screed aims to both correct the overall plane of the floor and level out local irregularities when covering the entire floor with a common layer of small thickness. On the practical side, sand concrete screed is the most acceptable and affordable way to prepare almost any floor for popular types of coatings: linoleum, laminate, vinyl type-setting or self-leveling floor.

What compounds to use

Traditionally, for screeding in residential premises, sand concrete is used in the proportion of 3.5 parts of sand to one part of grade 300 cement. In technical premises, the binder should be replaced with Portland cement of grade 400. With a screed layer up to 50 mm, this composition is optimal.

Thicker layers may require larger filler. It is allowed to use granite screenings and crumbs, expanded clay and crushed stone of a fine fraction. Filler larger than 15 mm is not recommended.

To improve some characteristics, frost-resistant additives, plasticizers and modifiers can be added to the mixture. To increase the fluidity of the mixture and make it easier to level, you can add about a tablespoon of dish detergent to 20-25 liters of water.

It is conditionally possible to call a screed and a self-leveling floor that does not require alignment with beacons. With a minimum layer of 10 mm, such a screed can cost a pretty penny, especially if the difference between the lowest and highest points exceeds 35-50 mm. It will be easier if you level the subfloor with ordinary sand concrete to eliminate the general difference, and after 2-3 days fill the self-leveling floor with the minimum possible layer.

Do I need reinforcement and insulation

Operating conditions of the floor can be completely different. If the layer thickness exceeds 40-50 mm, the coating may not tolerate thermal expansion and seasonal fluctuations of the building. With a 70-80 mm screed, the formation of cracks is practically guaranteed. If for linoleum and type-setting coatings this is quite tolerable, then bulk compositions will reflect all screed defects on themselves.

To strengthen the screed, use a nylon or steel mesh with a mesh of 30-60 mm and reinforced (welded) crossings. The synthetic mesh is stretched on self-tapping screws screwed into the preparatory floor, or on thin knitting needles made of knitting wire, fixed in the bedding. It is also possible to lay the mesh in a freshly poured mixture. Due to their own high rigidity, steel reinforcing meshes can be placed on remote "chairs".

Cement floor insulation is also widely practiced. First of all, when the screed is used as an accumulation layer for underfloor heating. Thermal insulation is carried out with materials resistant to uniform compression: expanded polystyrene and polyurethane boards. The thickness of the screed must be at least 30 mm with mandatory synthetic reinforcement. When laying the insulation on the bedding, preliminary leveling with washed sand is required with a layer of 50-70 mm.

Work order

The first step before pouring is to eliminate absolutely all gaps and crevices through which water can seep. Hollow floor slabs promise another danger: water can flow into them and not flow out from below. A damp ceiling and a swelling floor are guaranteed in the next six months, damage to the power grid laid inside the voids is possible.

Waterproofing should be done even by a private developer: the rapid outflow of water from the mass does not allow the hydration of the cement in the mixture to complete, which is why the floor will not gain the necessary strength. The controversial question about the screed on the bulk layer: how in this case to prevent seepage? Here it is necessary to fill in two layers with a time interval of at least a day. The first layer is poured directly onto the bedding, although more and more often it is first covered with geotextiles so that the water does not entrain the cement. The upper layer will then have time to form normally, and the residual laitance flow will strengthen the underlying masses. The second version is also suitable for a wooden floor: the cavity to be filled is lined with a polyethylene film hermetically joined at the seams.

After the floor is sealed and waterproofed, we lay out the reinforcing mesh on remote supports. Next, we give a zero mark on the walls and install beacons. Pure alabaster should not be used here, it shrinks. Beacons can be quickly installed by mixing building gypsum into a solution of a freshly prepared batch. After applying small tubercles to the floor, we lay the first strip of the lighthouse 10-15 cm from the wall and align it with the lacing. The second and subsequent strips are installed according to the rack or laser level, after laying every third beacon, the common plane is checked by the rule.

Usually, pouring is carried out by two workers: one prepares the batch, and the other sets the next 2-3 beacons on the remnants of the previously mixed mass.

Subfloor post-processing

Speaking about the thickness of the screed, we always mean the final value after surface treatment. Depending on the floor covering, the floor can be processed in different ways, while the thickness can either decrease or increase within 0.5 mm.

The two most well-known processing methods are grinding and ironing. The first aims to get rid of the upper layer formed by a fine fraction of sand and rare milk, which will wipe unevenly, creak and dust. Grinding is performed after two weeks of drying of the screed. Ironing, on the contrary, is carried out immediately after the sand concrete has set, and its purpose is exactly the opposite - to strengthen the top layer.

If the surface of the screed is not exploited, it is allowed not to perform such processing. For laminate, parquet and other type-setting coatings, it is better to impregnate the screed with a primer, and then wash it thoroughly. The difference here is linoleum - under it the screed is impregnated with diluted 1: 1 polyvinyl adhesive.

In order to lay the tiles qualitatively and evenly, grouting is performed on top of the primed screed with an adhesive composition that will be used when tiling. This helps to smooth out the remaining irregularities, reduce the screed layer above the insulation to 20 mm using a fiberglass facade mesh, and improve adhesion. After drying, the surface is treated with a grinding wheel to remove the “glaze” that prevents deep absorption of the tile adhesive.

The article contains general information on the installation of a cement-sand floor screed in an apartment.

I note that the installation of a cement-sand screed in an apartment is rarely used, with the advent of light (by weight) screeds, more suitable for multi-storey residential buildings. However, the DSP screed is the cheapest.

Marking the level of the floor screed

Floor screed in the apartment begins with markings. Marking begins after removing all old coatings, if any, to the frame base of the house.

First, using or a laser level, the top level of the floor screed is marked. With a measuring tool, it is necessary to find the places of the floor that are most raised relative to the rest of the floor. This will be the zero level of the floor screed. On the walls of the room, marks of the zero (currently highest) floor level are made. At the zero level, beacons are installed strictly in a single horizontal level. Lighthouses will serve as the level of the screed (new floor).

! Lighthouses are flat metal slats that are laid in a level on the subfloor and along which the screed solution is leveled using a long building level.

Beacons for floor screed. (not the best ones)

Reinforcement of cement-sand floor screed

! Cement-sand screed is made only with reinforcement.

For the strength of the screed, a metal reinforcing mesh is laid on the base of the floor. The mesh will reduce the thickness of the screed to 5 cm without impairing its properties. Grid cells should be 100 × 100 mm. The mesh must be raised above the base by 3-4 cm so that the reinforced mesh is inside the screed layer. In the photo, the reinforcement is not done quite correctly. The grid needs to be raised by 3-4 cm, and the beacons should be leveled.

Floor waterproofing and beacons for gypsum board profile screed

Damper tape and waterproofing

! On the wall around the entire perimeter of the room, install a damper tape (a strip of insulator to compensate for the expansion of the screed).

On the draft floor you need to put waterproofing. It can be polyethylene from 200 microns. It overlaps 20 cm. And also, it can be any rolled waterproofing material, it also overlaps, but 10-15 cm. The photo continues the example of how not to make a DSP screed in an apartment.

An example of a cement-sand screed device.

Cement-sand screed dries for a long time

! In fact, the cement-sand screed does not dry for a long time, but gains the necessary strength for a long time. You can walk on the CPS screed in a day.

After screeding the entire floor of the room, and this must be done in one day, the screed must be covered with plastic wrap for a uniform set of cement of its monolithic properties. The cement-sand screed dries for 21-28 days. For faster drying of the screed, polymer additives (plasticizer) are added to it. The plasticizer allows you to reduce the drying time of the solution.

Alternative to cement-sand screed

Instead of the classic "wet" cement-sand screed, technology can be applied. This will significantly speed up the readiness of the screed for further work.

Important! When setting the screed strength, drafts and drying with heat guns are not allowed. For the first 2-3 days, a new screed should be moistened with plenty of cold water using a paint roller. This operation is called pouring the screed.

Floor screed drying time

The minimum layer of cement-sand screed with a reinforcing mesh is 5 cm. The time for complete drying of a cement-sand screed based on M 150 cement is 21 days. You can walk on the screed after 2-3 days.

A few more tips for installing floor screed in the apartment

1. When marking the floor screed, remember the thickness of the future new floor covering. If it has different thicknesses in different rooms, then the screed will have to be made of different thicknesses. By changing the thickness of the screed by room, you can make the entire floor in the apartment into one level. 2. For small differences in floor level, use not screeds for leveling, but "". The thickness of their fill is from 1-2 cm. 3. If the markings show giant differences in floor level in different rooms, then a cement-sand screed will not work because of its weight. In this case, to level the floor, dry floor screed methods or a screed device on a cushion of expanded clay concrete are used. 4. Another option is the device of expanded clay (perlite) screed. This type of screed involves the addition of light backfill materials (expanded clay, perlite, vermiculite) to the cement-sand mortar. They reduce all ties, which is good for high-rise buildings. However, these screeds are not suitable for heavily loaded floors.

5. Before any screed, it is necessary to waterproof the floor. Lubricate the corners of the floor, as well as pre-sealed technical holes in the floor, with special waterproofing mastics. 6. I do not recommend using perforated plaster beacons for screeds. However, if you already use them, you can not remove them from the floor screed. 7. Removed from the screed after the screed has set, only large beacons, for which both metal square pipes and even wooden slats and drywall profiles could be adapted. Beacons need to be removed 2 days after pouring the screed. The recesses remaining in the screed after removing the beacons are sealed with the same solution from which the screed is made.

That's all! The floor screed in the apartment is arranged. Good luck in your endeavors!